A) I would say lisps are rather boring. Clojure, one of the most recent ones hasn't changed in 15 years. B) most systems are built in C, Java, Python. So no wonder most complex systems are written in those.

There is significant 'political' pressure to use whatever is already used and has the libraries. That's C, C++, Java, etc. most of the time. If the libraries and tools were truly language independent then I'm certain more companies would choose languages like CL more frequently for their merits.

"Whatever already has the libraries" isn't political. It's technical. It's thousands of lines of code that you don't have to write, and don't have to debug, and don't have to maintain.

And having relevant libraries is (at least part of) "the merits".

Right, but at some point, Python didn’t have all those libraries. But it did have a growing community who wanted to write them, even when it was to wrap perform at C++ or Fortran code.

There's a huge ecosystem of old Java code that is fully usable from Scala or Clojure, including stuff like bindings for native SQLite. Good FFI lets us move beyond old languages.

Also there's ABCL. Yet, I have never personally been in a company or heard of a colleague where they were allowed to deviate from Java or C#. Many times it was a struggle to even get IntelliJ licenses.

Don’t know about Clojure but in Scala that tends to be awkward and not preferred.

From Clojure, Java interop is pretty smooth in most cases. Perhaps Clojure being dynamic helps in that regard.

It's not that it won't work; it's that the idioms Scala is written with are different than Java, so having Java-like code mixed in messes up the coherence of the project. Not such an obstacle that you wouldn't ever do it, but enough that you'd prefer one designed for Scala if it is available.

Well, as the Italians say, "yes, and if my grandmother had wheels she'd be a bicycle."